一、概況
1、概念
pgsql高可用集群采用postgresql+etcd+patroni+haproxy+keepalived等軟件實現，以postgresql做數據庫，etcd存儲集群狀態，patroni與etcd結合實現數據庫集群故障切換，
haproxy實現數據庫高可用（讀讀寫分離），keepalived實現VIP跳轉。
2、拓撲圖
軟件下載地址：
鏈接：https://pan.baidu.com/s/1VIWwXcfQRCumJjEXndSXPQ
提取碼：5bpz
二、postgresql部署（三個節點）
1、下載解壓
https://www.enterprisedb.com/download-postgresql-binaries mkdir -p /data/pg_data tar xf postgresql-10.18-1-linux-x64-binaries.tar.gz -C /data/
2、創建用戶並授權
useradd postgres passwd postgres chown -R postgres.postgres /data/
3、初始化數據庫（postgres用戶下）
切換目錄 [root@centos7 ~]# su – postgres 初始化目錄 [postgres@centos7 ~]$ /data/pgsql/bin/initdb -D /data/pg_data/
4、配置變量
su – postgres vim .bash_profile PATH=$PATH:$HOME/bin export PATH export PATH export PGHOME=/data/pgsql export PATH=$PATH:$PGHOME/bin export PGDATA=/data/pg_data export PGLOG=/data/pg_log/pg.log source .bash_profile mkdir -p /data/pg_log chown postgres.postgres /data/pg_data chown postgres.postgres /data/pg_log
5、配置postgresql啟動腳本
vim /etc/systemd/system/postgresql.service [Unit] Description=PostgreSQL database server After=network.target [Service] Type=forking User=postgres Group=postgres ExecStart= /data/pgsql/bin/pg_ctl -D /data/pg_data/ start ExecReload= /data/pgsql/bin/pg_ctl -D /data/pg_data/ restart ExecStop= /data/pgsql/bin/pg_ctl -D /data/pg_data/ stop PrivateTmp=true [Install] WantedBy=multi-user.target
6、啟動與關閉
systemctl daemon-reload 開啟 systemctl start postgresql 關閉 systemctl stop postgresql 重啟 systemctl restart postgresql
7、數據庫添加密碼
[postgres@pgsql-19 ~]$ psql -U postgres -h localhost postgres=# alter user postgres with password 'P@sswrd';
8、允許遠程連接
vim /data/pg_data/pg_hba.conf host all all 0.0.0.0/0 md5
vim /data/pg_data/postgresql.conf listen_addresses = '*' password_encryption = on 重啟數據庫 systemctl restart postgresql
三、etcd部署（三個節點）
1、下載解壓
tar xf etcd-v3.1.20-linux-amd64.tar.gz -C /usr/local/ ln -s /usr/local/etcd-v3.1.20-linux-amd64 /usr/local/etcd
2、文件配置
mkdir -p /usr/local/etcd/data/etcd vim /usr/local/etcd/conf.yml name: pgsql_1971 data-dir: /usr/local/etcd/data/etcd listen-client-urls: http://192.168.19.71:2379,http://127.0.0.1:2379 advertise-client-urls: http://192.168.19.71:2379,http://127.0.0.1:2379 listen-peer-urls: http://192.168.19.71:2380 initial-advertise-peer-urls: http://192.168.19.71:2380 initial-cluster: pgsql_1971=http://192.168.19.71:2380,pgsql_1972=http://192.168.19.72:2380,pgsql_1973=http://192.168.19.73:2380 initial-cluster-token: etcd-cluster-token initial-cluster-state: new mkdir -p /usr/local/etcd/data/etc vim /usr/local/etcd/conf.yml name: pgsql_1972 data-dir: /usr/local/etcd/data/etcd listen-client-urls: http://192.168.19.72:2379,http://127.0.0.1:2379 advertise-client-urls: http://192.168.19.72:2379,http://127.0.0.1:2379 listen-peer-urls: http://192.168.19.72:2380 initial-advertise-peer-urls: http://192.168.19.72:2380 initial-cluster: pgsql_1971=http://192.168.19.71:2380,pgsql_1972=http://192.168.19.72:2380,pgsql_1973=http://192.168.19.73:2380 initial-cluster-token: etcd-cluster-token initial-cluster-state: new mkdir -p /usr/local/etcd/data/etc vim /usr/local/etcd/conf.yml name: pgsql_1973 data-dir: /usr/local/etcd/data/etcd listen-client-urls: http://192.168.19.73:2379,http://127.0.0.1:2379 advertise-client-urls: http://192.168.19.73:2379,http://127.0.0.1:2379 listen-peer-urls: http://192.168.19.73:2380 initial-advertise-peer-urls: http://192.168.19.73:2380 initial-cluster: pgsql_1971=http://192.168.19.71:2380,pgsql_1972=http://192.168.19.72:2380,pgsql_1973=http://192.168.19.73:2380 initial-cluster-token: etcd-cluster-token initial-cluster-state: new
3、啟動並加入到開機自啟中
加入開機自啟里邊 nohup /usr/local/etcd/etcd --config-file=/usr/local/etcd/conf.yml &
4、集群檢查
netstat -lntup|grep etcd /usr/local/etcd/etcdctl member list
四、patroni部署（三個節點）
1、更新postgresql.conf文件
postgresql.conf配置如下
max_connections = '500'
max_wal_senders = '10'
port = '5432'
listen_addresses = '*'
synchronous_commit = on
full_page_writes = on
wal_log_hints = on
synchronous_standby_names = '*'
max_replication_slots = 10
wal_level = replica
注：wal_log_hints = on，synchronous_standby_names = '*' 這兩個參數會導致數據庫執行呆滯，后來者歡迎留言看是怎么回事兒
2、更新pg_hba.conf文件
vim /data/pg_data/pg_hba.conf 清理最后配置的配置，新增以下 local all all peer host all all 127.0.0.1/32 md5 host all postgres 127.0.0.1/32 md5 host all all 192.168.19.0/24 md5 host all all ::1/128 md5 local replication replicator peer host replication replicator 127.0.0.1/32 md5 host replication replicator ::1/128 md5 host replication replicator 192.168.19.71/32 md5 host replication replicator 192.168.19.72/32 md5 host replication replicator 192.168.19.73/32 md5
以上配置完成后，重啟數據庫
3、在主節點上創建復制槽，很重要，patroni會用到
postgres=# create user replicator replication login encrypted password '1qaz2wsx';
4、配置stream replication（在兩個從節點操作）
systemctl stop postgresql
su - postgres cd /data/ && rm -rf pg_data /data/pgsql/bin/pg_basebackup -h 192.168.19.71 -D /data/pg_data -U replicator -v -P -R
啟動數據庫
systemctl start postgresql
5、安裝patroni（三個節點）
yum install -y python3 python-psycopg2 python3-devel pip3 install --upgrade pip pip3 install psycopg2-binary -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com pip3 install patroni[etcd] -i http://pypi.douban.com/simple/ --trusted-host pypi.douban.com 驗證是否安裝成功 which patroni patronictl --help
6、創建patroni配置文件
mkdir -p /usr/patroni/conf cd /usr/patroni/conf/
node1
scope: batman
namespace: /service/
name: postgresql1
restapi:
listen: 192.168.19.71:8008
connect_address: 192.168.19.71:8008
# certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
# keyfile: /etc/ssl/private/ssl-cert-snakeoil.key
# authentication:
# username: username
# password: password
# ctl:
# insecure: false # Allow connections to SSL sites without certs
# certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
# cacert: /etc/ssl/certs/ssl-cacert-snakeoil.pem
etcd:
#Provide host to do the initial discovery of the cluster topology:
host: 192.168.19.71:2379
#Or use "hosts" to provide multiple endpoints
#Could be a comma separated string:
#hosts: host1:port1,host2:port2
#host: 192.168.19.71:2379,192.168.19.71:2379,192.168.19.73:2379
#or an actual yaml list:
#hosts:
#- host1:port1
#- host2:port2
#Once discovery is complete Patroni will use the list of advertised clientURLs
#It is possible to change this behavior through by setting:
#use_proxies: true
#raft:
# data_dir: .
# self_addr: 192.168.19.71:2222
# partner_addrs:
# - 192.168.19.71:2223
# - 192.168.19.71:2224
bootstrap:
# this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
# and all other cluster members will use it as a `global configuration`
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
# master_start_timeout: 300
# synchronous_mode: false
#standby_cluster:
#host: 192.168.19.71
#port: 1111
#primary_slot_name: patroni
postgresql:
use_pg_rewind: true
# use_slots: true
parameters:
# wal_level: hot_standby
# hot_standby: "on"
# max_connections: 100
# max_worker_processes: 8
# wal_keep_segments: 8
# max_wal_senders: 10
# max_replication_slots: 10
# max_prepared_transactions: 0
# max_locks_per_transaction: 64
# wal_log_hints: "on"
# track_commit_timestamp: "off"
# archive_mode: "on"
# archive_timeout: 1800s
# archive_command: mkdir -p ../wal_archive && test ! -f ../wal_archive/%f && cp %p ../wal_archive/%f
# recovery_conf:
# restore_command: cp ../wal_archive/%f %p
# some desired options for 'initdb'
initdb: # Note: It needs to be a list (some options need values, others are switches)
- encoding: UTF8
- data-checksums
pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
# For kerberos gss based connectivity (discard @.*$)
#- host replication replicator 192.168.19.71/32 gss include_realm=0
#- host all all 0.0.0.0/0 gss include_realm=0
- host replication replicator 192.168.19.71/32 md5
- host all all 0.0.0.0/0 md5
# - hostssl all all 0.0.0.0/0 md5
# Additional script to be launched after initial cluster creation (will be passed the connection URL as parameter)
# post_init: /usr/local/bin/setup_cluster.sh
# Some additional users users which needs to be created after initializing new cluster
users:
admin:
password: admin
options:
- createrole
- createdb
postgresql:
listen: 192.168.19.71:5432
connect_address: 192.168.19.71:5432
data_dir: /data/pg_data
bin_dir: /data/pgsql/bin
# config_dir:
pgpass: /tmp/pgpass0
authentication:
replication:
username: replicator
password: 1qaz2wsx
superuser:
username: postgres
password: P@sswrd
rewind: # Has no effect on postgres 10 and lower
username: postgres
password: P@sswrd
# Server side kerberos spn
# krbsrvname: postgres
parameters:
# Fully qualified kerberos ticket file for the running user
# same as KRB5CCNAME used by the GSS
# krb_server_keyfile: /var/spool/keytabs/postgres
unix_socket_directories: '.'
# Additional fencing script executed after acquiring the leader lock but before promoting the replica
#pre_promote: /path/to/pre_promote.sh
#watchdog:
# mode: automatic # Allowed values: off, automatic, required
# device: /dev/watchdog
# safety_margin: 5
tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false
------------------------------------------------------------------------------
node2
scope: batman
namespace: /service/
name: postgresql2
restapi:
listen: 192.168.19.72:8008
connect_address: 192.168.19.72:8008
# certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
# keyfile: /etc/ssl/private/ssl-cert-snakeoil.key
# authentication:
# username: username
# password: password
# ctl:
# insecure: false # Allow connections to SSL sites without certs
# certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
# cacert: /etc/ssl/certs/ssl-cacert-snakeoil.pem
etcd:
#Provide host to do the initial discovery of the cluster topology:
host: 192.168.19.72:2379
#Or use "hosts" to provide multiple endpoints
#Could be a comma separated string:
#hosts: host1:port1,host2:port2
#host: 192.168.19.71:2379,192.168.19.72:2379,192.168.19.73:2379
#or an actual yaml list:
#hosts:
#- host1:port1
#- host2:port2
#Once discovery is complete Patroni will use the list of advertised clientURLs
#It is possible to change this behavior through by setting:
#use_proxies: true
#raft:
# data_dir: .
# self_addr: 192.168.19.72:2222
# partner_addrs:
# - 192.168.19.72:2223
# - 192.168.19.72:2224
bootstrap:
# this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
# and all other cluster members will use it as a `global configuration`
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
# master_start_timeout: 300
# synchronous_mode: false
#standby_cluster:
#host: 192.168.19.72
#port: 1111
#primary_slot_name: patroni
postgresql:
use_pg_rewind: true
# use_slots: true
parameters:
# wal_level: hot_standby
# hot_standby: "on"
# max_connections: 100
# max_worker_processes: 8
# wal_keep_segments: 8
# max_wal_senders: 10
# max_replication_slots: 10
# max_prepared_transactions: 0
# max_locks_per_transaction: 64
# wal_log_hints: "on"
# track_commit_timestamp: "off"
# archive_mode: "on"
# archive_timeout: 1800s
# archive_command: mkdir -p ../wal_archive && test ! -f ../wal_archive/%f && cp %p ../wal_archive/%f
# recovery_conf:
# restore_command: cp ../wal_archive/%f %p
# some desired options for 'initdb'
initdb: # Note: It needs to be a list (some options need values, others are switches)
- encoding: UTF8
- data-checksums
pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
# For kerberos gss based connectivity (discard @.*$)
#- host replication replicator 192.168.19.72/32 gss include_realm=0
#- host all all 0.0.0.0/0 gss include_realm=0
- host replication replicator 192.168.19.72/32 md5
- host all all 0.0.0.0/0 md5
# - hostssl all all 0.0.0.0/0 md5
# Additional script to be launched after initial cluster creation (will be passed the connection URL as parameter)
# post_init: /usr/local/bin/setup_cluster.sh
# Some additional users users which needs to be created after initializing new cluster
users:
admin:
password: admin
options:
- createrole
- createdb
postgresql:
listen: 192.168.19.72:5432
connect_address: 192.168.19.72:5432
data_dir: /data/pg_data
bin_dir: /data/pgsql/bin
# config_dir:
pgpass: /tmp/pgpass0
authentication:
replication:
username: replicator
password: 1qaz2wsx
superuser:
username: postgres
password: P@sswrd
rewind: # Has no effect on postgres 10 and lower
username: postgres
password: P@sswrd
# Server side kerberos spn
# krbsrvname: postgres
parameters:
# Fully qualified kerberos ticket file for the running user
# same as KRB5CCNAME used by the GSS
# krb_server_keyfile: /var/spool/keytabs/postgres
unix_socket_directories: '.'
# Additional fencing script executed after acquiring the leader lock but before promoting the replica
#pre_promote: /path/to/pre_promote.sh
#watchdog:
# mode: automatic # Allowed values: off, automatic, required
# device: /dev/watchdog
# safety_margin: 5
tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false
------------------------------------------------------------------------------
node3
scope: batman
namespace: /service/
name: postgresql3
restapi:
listen: 192.168.19.73:8008
connect_address: 192.168.19.73:8008
# certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
# keyfile: /etc/ssl/private/ssl-cert-snakeoil.key
# authentication:
# username: username
# password: password
# ctl:
# insecure: false # Allow connections to SSL sites without certs
# certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
# cacert: /etc/ssl/certs/ssl-cacert-snakeoil.pem
etcd:
#Provide host to do the initial discovery of the cluster topology:
host: 192.168.19.73:2379
#Or use "hosts" to provide multiple endpoints
#Could be a comma separated string:
#hosts: host1:port1,host2:port2
#host: 192.168.19.73:2379,192.168.19.73:2379,192.168.19.73:2379
#or an actual yaml list:
#hosts:
#- host1:port1
#- host2:port2
#Once discovery is complete Patroni will use the list of advertised clientURLs
#It is possible to change this behavior through by setting:
#use_proxies: true
#raft:
# data_dir: .
# self_addr: 192.168.19.73:2222
# partner_addrs:
# - 192.168.19.73:2223
# - 192.168.19.73:2224
bootstrap:
# this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
# and all other cluster members will use it as a `global configuration`
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
# master_start_timeout: 300
# synchronous_mode: false
#standby_cluster:
#host: 192.168.19.73
#port: 1111
#primary_slot_name: patroni
postgresql:
use_pg_rewind: true
# use_slots: true
parameters:
# wal_level: hot_standby
# hot_standby: "on"
# max_connections: 100
# max_worker_processes: 8
# wal_keep_segments: 8
# max_wal_senders: 10
# max_replication_slots: 10
# max_prepared_transactions: 0
# max_locks_per_transaction: 64
# wal_log_hints: "on"
# track_commit_timestamp: "off"
# archive_mode: "on"
# archive_timeout: 1800s
# archive_command: mkdir -p ../wal_archive && test ! -f ../wal_archive/%f && cp %p ../wal_archive/%f
# recovery_conf:
# restore_command: cp ../wal_archive/%f %p
# some desired options for 'initdb'
initdb: # Note: It needs to be a list (some options need values, others are switches)
- encoding: UTF8
- data-checksums
pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
# For kerberos gss based connectivity (discard @.*$)
#- host replication replicator 192.168.19.73/32 gss include_realm=0
#- host all all 0.0.0.0/0 gss include_realm=0
- host replication replicator 192.168.19.73/32 md5
- host all all 0.0.0.0/0 md5
# - hostssl all all 0.0.0.0/0 md5
# Additional script to be launched after initial cluster creation (will be passed the connection URL as parameter)
# post_init: /usr/local/bin/setup_cluster.sh
# Some additional users users which needs to be created after initializing new cluster
users:
admin:
password: admin
options:
- createrole
- createdb
postgresql:
listen: 192.168.19.73:5432
connect_address: 192.168.19.73:5432
data_dir: /data/pg_data
bin_dir: /data/pgsql/bin
# config_dir:
pgpass: /tmp/pgpass0
authentication:
replication:
username: replicator
password: 1qaz2wsx
superuser:
username: postgres
password: P@sswrd
rewind: # Has no effect on postgres 10 and lower
username: postgres
password: P@sswrd
# Server side kerberos spn
# krbsrvname: postgres
parameters:
# Fully qualified kerberos ticket file for the running user
# same as KRB5CCNAME used by the GSS
# krb_server_keyfile: /var/spool/keytabs/postgres
unix_socket_directories: '.'
# Additional fencing script executed after acquiring the leader lock but before promoting the replica
#pre_promote: /path/to/pre_promote.sh
#watchdog:
# mode: automatic # Allowed values: off, automatic, required
# device: /dev/watchdog
# safety_margin: 5
tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false
7、依次啟動patroni服務
Postgres用戶下啟動 nohup patroni /usr/patroni/conf/patroni_postgresql.yml &
8、patroni配置啟動腳本
為了方便開機自啟，故配置成 patroni.service，3個node都需要進行配置，配置好patroni.service后就可以直接在root用戶下切換Leader以及重啟postgres節點等操作
[root@pgsql_1971 ~]$ vim /etc/systemd/system/patroni.service [Unit] Description=patroni - a high-availability PostgreSQL Documentation=https://patroni.readthedocs.io/en/latest/index.html After=syslog.target network.target etcd.target Wants=network-online.target [Service] Type=simple User=postgres Group=postgres PermissionsStartOnly=true ExecStart=/usr/local/bin/patroni /usr/patroni/conf/patroni_postgresql.yml ExecReload=/bin/kill -HUP $MAINPID LimitNOFILE=65536 KillMode=process KillSignal=SIGINT Restart=on-abnormal RestartSec=30s TimeoutSec=0 [Install] WantedBy=multi-user.target
9、禁用postgresql腳本采用patroni服務啟動數據庫
禁止 postgresql 的自啟動，通過 patroni 來管理 postgresql systemctl stop postgresql systemctl status postgresql systemctl disable postgresql systemctl status patroni systemctl start patroni systemctl enable patroni
五、集群檢查
1、數據庫集群檢查
patronictl -c /usr/patroni/conf/patroni_postgresql.yml list
2、etcd檢查
root@pgsql_1971 ~]# /usr/local/etcd/etcdctl ls /service/batman
root@pgsql_1971 ~]# /usr/local/etcd/etcdctl get /service/batman/members/postgresql1
六、haproxy部署（兩個從節點）
1、安裝haproxy服務
yum install -y haproxy cp -r /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg_bak
2、配置文件
vi /etc/haproxy/haproxy.cfg
#---------------------------------------------------------------------
# 全局定義
global
# log語法：log [max_level_1]
# 全局的日志配置，使用log關鍵字，指定使用127.0.0.1上的syslog服務中的local0日志設備，
# 記錄日志等級為info的日志
# log 127.0.0.1 local0 info
log 127.0.0.1 local1 notice
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
# 定義每個haproxy進程的最大連接數 ，由於每個連接包括一個客戶端和一個服務器端，
# 所以單個進程的TCP會話最大數目將是該值的兩倍。
maxconn 4096
# 用戶，組
user haproxy
group haproxy
# 以守護進程的方式運行
daemon
# turn on stats unix socket
stats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# 默認部分的定義
defaults
# mode語法：mode {http|tcp|health} 。http是七層模式，tcp是四層模式，health是健康檢測，返回OK
mode tcp
# 使用127.0.0.1上的syslog服務的local3設備記錄錯誤信息
log 127.0.0.1 local3 err
#if you set mode to http,then you nust change tcplog into httplog
option tcplog
# 啟用該項，日志中將不會記錄空連接。所謂空連接就是在上游的負載均衡器或者監控系統為了
#探測該服務是否存活可用時，需要定期的連接或者獲取某一固定的組件或頁面，或者探測掃描
#端口是否在監聽或開放等動作被稱為空連接；官方文檔中標注，如果該服務上游沒有其他的負
#載均衡器的話，建議不要使用該參數，因為互聯網上的惡意掃描或其他動作就不會被記錄下來
option dontlognull
# 定義連接后端服務器的失敗重連次數，連接失敗次數超過此值后將會將對應后端服務器標記為不可用
retries 3
# 當使用了cookie時，haproxy將會將其請求的后端服務器的serverID插入到cookie中，以保證
#會話的SESSION持久性；而此時，如果后端的服務器宕掉了，但是客戶端的cookie是不會刷新的
#，如果設置此參數，將會將客戶的請求強制定向到另外一個后端server上，以保證服務的正常
option redispatch
#等待最大時長 When a server's maxconn is reached, connections are left pending in a queue which may be server-specific or global to the backend.
timeout queue 525600m
# 設置成功連接到一台服務器的最長等待時間，默認單位是毫秒
timeout connect 10s
# 客戶端非活動狀態的超時時長 The inactivity timeout applies when the client is expected to acknowledge or send data.
timeout client 525600m
# Set the maximum inactivity time on the server side.The inactivity timeout applies when the server is expected to acknowledge or send data.
timeout server 525600m
timeout check 5s
maxconn 5120
#---------------------------------------------------------------------
# 配置haproxy web監控，查看統計信息
listen status
bind 0.0.0.0:1080
mode http
log global
stats enable
# stats是haproxy的一個統計頁面的套接字，該參數設置統計頁面的刷新間隔為30s
stats refresh 30s
stats uri /haproxy-stats
# 設置統計頁面認證時的提示內容
stats realm Private lands
# 設置統計頁面認證的用戶和密碼，如果要設置多個，另起一行寫入即可
stats auth admin:passw0rd
# 隱藏統計頁面上的haproxy版本信息
# stats hide-version
#---------------------------------------------------------------------
listen master
bind *:5000
mode tcp
option tcplog
balance roundrobin
option httpchk OPTIONS /master
http-check expect status 200
default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
server node1 192.168.19.71:5432 maxconn 1000 check port 8008 inter 5000 rise 2 fall 2
server node2 192.168.19.72:5432 maxconn 1000 check port 8008 inter 5000 rise 2 fall 2
server node3 192.168.19.73:5432 maxconn 1000 check port 8008 inter 5000 rise 2 fall 2
listen replicas
bind *:5001
mode tcp
option tcplog
balance roundrobin
option httpchk OPTIONS /replica
http-check expect status 200
default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
server node1 192.168.19.71:5432 maxconn 1000 check port 8008 inter 5000 rise 2 fall 2
server node2 192.168.19.72:5432 maxconn 1000 check port 8008 inter 5000 rise 2 fall 2
server node3 192.168.19.73:5432 maxconn 1000 check port 8008 inter 5000 rise 2 fall 2
3、啟動服務並加入開機自啟
systemctl start haproxy systemctl enable haproxy systemctl status haproxy 瀏覽器訪問http://192.168.19.72:1080/haproxy-stats輸入用戶名admin密碼passw0rd 這里我們通過5000端口和5001端口分別來提供寫服務和讀服務,如果需要對數據庫寫入數據只需要對外提供192.168.216.136:5000即可,可以模擬主庫故障，即關閉其中的master節點來驗證是否會進行自動主從切換
七、keepalived部署（兩個從節點）
1、安裝keepalived服務
yum install -y keepalived
2、配置更新
pg-node1
cat keepalived.conf
global_defs {
notification_email {
root@localhost #收郵件人
}
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id master-node
router_id LVS_01
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1221
}
virtual_ipaddress {
192.168.19.110/24 dev eth0 label eth0:0
}
}
-------------------------------------------------------------------------------
pg-node2
cat keepalived.conf
!Configuration File for keepalived
global_defs {
notification_email {
root@localhost #收郵件人
}
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id master-node
router_id LVS_02
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1221
}
virtual_ipaddress {
192.168.19.110/24 dev eth0 label eth0:0
}
}
3、啟動keepalived服務
systemctl restart keepalived systemctl enable keepalived
4、對外提供訪問端口
VIP：192.168.19.110 端口：5000 讀寫權限 端口：5001 讀權限
注：以上部署有個問題就是haproxy與keepalived相互依存的問題，我的觀點是除非死機否則不切換，所以我沒有做腳本控制，其他要是有問題，歡迎大佬們提提意見哦！！！